Bottle caps can generally be removed from glass beverage bottles by one of two methods: The cap may either be twisted off; or it may be pried off. By far, the most common method of prying caps off of bottles involves the use of a bottle opening tool having a handle, an intermediate hook, and an end fulcrum.
Typically, prior intermediate hook and end fulcrum-type bottle openers all have extended handles which the operator of the opener pulls up on in order to remove the cap from the bottle. In most cases the handle is several inches long, thereby effecting a relatively high mechanical advantage, and providing ample length to be grasped in the hand of the operator. U.S. Pat. No. Des. 51,962 is an example of this prior type of bottle opener.
A problem with such prior devices is that the openers can be easily lost, misplaced, borrowed, or stolen when they are not in use. This may be a particular problem for a professional bar tender who puts down his opener, for example, to mix drinks, and subsequently has to search for the misplaced opener before opening another bottled beverage.
Another problem of such prior devices is that in order to provide ample leverage to pry the cap open, the typical handles of such devices are relatively long-(typically 4 to 6 inches). In order to use such prior devices the operator must use his entire hand (or in any event, all the fingers of one hand) to grasp and lift the opener handle. Accordingly, with such prior devices the operator must release everything else from this hand in order to use the opener.
Another problem of such prior devices is that because the handles are several inches long they require a corresponding amount of space for storage. Not only can this characteristic of such prior openers make storage difficult, but it also renders such tools awkward to carry around.
In order to make bottle openers more compact, and thus more transportable, various designs have been proposed, each of which effectively reduces the length of the handle. In some cases, (such as U.S. Pat. No. 631,872), the handle is simply collapsible and folds out when in use to provide sufficient mechanical advantage; in other cases (such as U.S. Pat. Nos. 1,578,627; 888,580; 3,495,284; and 2,548,517) rings are provided for the fingers or knuckles to compensate for the reduced leverage provided by such tools. A problem with the former (i.e. collapsible) design is that it actually takes two hands to operate (i.e. open) the tool, and the hook of such devices must inherently be of narrow width. A problem with the latter (i.e. finger and knuckle ring-type levers) is that they are awkward and painful to operate over long periods of time.
In order to alleviate the problems discussed above which are associated with prior handle-hook-fulcrum type bottle openers, many bottled beverages are provided with caps which can be opened both by bottle openers and by hand-twisting of the cap. However, It has been found by professional bar tenders that, when large numbers (i.e. dozens) of bottles are to be opened at a time, such "twist" caps can be more easily, more efficiently, and more quickly removed by using a handle-hook-fulcrum type bottle opening tool.